1. Field of the Invention
The invention relates to recycle of secondary batteries (including recycling, muse, remanufacturing, and so forth) and particularly to a recycling technology for non-aqueous electrolyte secondary batteries used as vehicle drive power sources.
2. Description of Related Art
For example, Japanese Patent Application Publication No. 2007-141464 (JP-2007-141464 A) proposes a secondary battery reuse system designed such that, even when a secondary battery system is disassembled, various information on the secondary battery modules constituting this system can be losslessly maintained. In this secondary battery reuse system, the electrical characteristic information and use history information of a secondary battery module are retrieved from the secondary battery module using external interface means, and a reuse grade classification is performed on the secondary battery module by a battery information management device based on the retrieved information.
However, while JP-2007-141464 A does teach the determination of whether or not a used secondary battery module is reusable by setting a threshold value for a property value of the secondary battery module for use in the reuse grade classification, it does not specify specific criteria and procedures according to the reuse configuration of the used secondary battery module.
For example, as a reuse configuration for a used secondary battery module, the case where the used secondary battery module is used in combination with an unused secondary battery module can be envisioned; however, the criteria for setting the threshold value for determining reusability in such a case and the criteria in connection with combining a used secondary battery module with an unused secondary battery module are unclear in the secondary battery reuse system described in JP-2007-141464 A. As a consequence, when an unused secondary battery module is used in combination with a used secondary battery module that has been rated as reusable, unexpected problems or malfunctions may be produced that are caused by variations in performance (non-uniformity, inconsistency) between the secondary battery modules.
This also applies to the case where a used secondary battery module is used in combination with a secondary battery module that has already been placed in use but is still usable as equivalent to the unused article (new article) as a secondary battery module unit.